Anterior cervical plates can be used for fixation of the cervical spine. The structure of the intervertebral disc disposed between the cervical bones comprises a peripheral fibrous shroud (the annulus) which circumscribes a spheroid of flexibly deformable material (the nucleus). The nucleus comprises a hydrophilic, elastomeric cartilaginous substance that cushions and supports the separation between the bones while also permitting articulation of the two vertebral bones relative to one another to the extent such articulation is allowed by the other soft tissue and bony structures surrounding the disc.
Traumatic, genetic, and long term wearing phenomena contribute to the degeneration of the nucleus. This degeneration of this critical disc material, from the hydrated, elastomeric material that supports the separation and flexibility of the vertebral bones, to a flattened and inflexible state, affects the mobility of the segment, and can cause significant pain. In many instances the vertebral bones are best if simply immobilized which is performed by securing two or more discs together.
Immobilization is achieved by attaching metal plates to the anterior or posterior elements of the cervical spine, and the insertion of some osteoconductive material (autograft, allograft, or other porous material) between the adjacent vertebrae of the segment. This sacrifice of mobility at the immobilized, or fused, segment, can affect the patient's surrounding joint segments.
The screws used to attach the plates required locking mechanisms to prevent premature loosening due to the rigidity of the plate. Numerous prior art references address such locking screws, however, the prior art fails to address the construction of the plate.
The use of an expandable balloon like artificial disc prosthesis filled with a polymer is known. A joint arthroplasty device can be formed in situ by inserting a hollow device having an aperture and a lumen into a target joint, and injecting material into the hollow device to form an implant. An artificial/prosthetic facet joint with balloon joint space component composed of latex, polymer, silicone or the like materials.
What is needed in the art is an anterior cervical disc that is formed from a polycarbonate having a fabric skeleton structure that can include an inflatable balloon to mimic the properties of the natural disc by maintaining the intervertebral disc space through a full range of natural motion and absorb the shocks of daily use.